I enjoyed this game in relaxed mode (match 2) but in challenge mode (match 3) I had the same problem as some other reviewers. I couldn't get by level 90. After trying a number of times and hours, I finally got the idea to change the setting to relaxed mode (match 2) at level 90. When I did, I could get by it. Then I changed it back to challenge mode for the next levels. I do like this game, it really makes you think and takes some strategy. However I got frustrated until I figured out how to get past level 90 in challenge mode.
I agree with other reviewers that this isn't exactly a traditional match three game but has a puzzle aspect. However, I really like it, probably because of that. It took me a little while to catch on to using all the features but now can play the levels fairly efficiently. My only wish is that there were more levels as I really enjoy it.